Base64 Decode
Decode Base64 or Base64URL back to text, with clear errors for invalid input.
Encode
Base64
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Allow anonymous usage statistics? UNQIRO would count only which tool was used, whether it finished and which links between the tools and the Format Lab were followed. Your files, text and results are never included, and this use is not counted.
Strict decoding
- Nothing is skipped: Characters outside the Base64 alphabet are reported with their position instead of being silently removed. Only spaces and line breaks are ignored.
- Padding is checked: Missing or extra = signs usually mean the text was cut off; the page says so.
- Files are recognised: If the decoded bytes are not text, you see their size, their kind (PNG, PDF, ZIP and the others the file tools know) and the first bytes, and you can download them as that file instead of seeing garbled characters.
Frequently asked questions
Why do I get "not valid UTF-8 text"?
The Base64 contains binary data, such as an image or compressed file, not text. Use the download button to save the bytes as a file.
Can it decode a JSON Web Token?
Yes, one part at a time: paste the header or payload (the parts between the dots). The signature is binary and will not decode as text.
Why is "=" padding sometimes missing?
Base64URL usually leaves it out. Both forms are accepted.